Parasomnias in children

Parasomnias in children are common and may consist of abnormal movements, behaviours, emotions, and autonomic activity during transitions between sleep states, from sleep to wakefulness, or during arousals from sleep.

Non-rapid eye movement (NREM) parasomnias include sleepwalking, night terrors, and confusional arousals, that occur most commonly in the first half of the night.

Rapid eye movement (REM) parasomnias occur later during the night and consist of experiences such as nightmares, recurrent isolated sleep paralysis, and REM sleep behaviour disorder (RBD). The latter is extremely rare in children.

The differential diagnosis includes seizures.

The three most common modifiable triggers for parasomnias in children include sleep deprivation, restless legs syndrome, and obstructive sleep apnoea. Treatment of these disorders may significantly reduce or resolve parasomnias in affected children.

Parasomnias are diagnosed on clinical grounds, based on descriptions from an observer, such as a parent or sibling who may share the bedroom. Ordinarily, a sleep study (diagnostic polysomnogram) is not necessary to establish the diagnosis. However, this test may be ordered when other comorbid primary sleep disorders, such as sleep apnoea, are suspected, and it is required for the diagnosis of RBD.

Management usually consists of treatment of the underlying cause of the parasomnia, reassurance, modification of the sleep environment, and, in adolescents, avoidance of substances such as caffeine and alcohol. When parasomnias become frequent and more problematic, occasionally pharmacological agents may be helpful.

The home environment needs to be modified to increase safety. This includes removal of any potentially dangerous items and sharp objects, locking doors, arranging for a sleeping space on the ground floor, and installation of door alarms.

Parasomnias are undesirable, non-deliberate motor or subjective phenomena that occur during the transition from one sleep state into another, from wakefulness into sleep, or during arousals from sleep.[1]Mahowald MW, Ettinger MG. Things that go bump in the night: the parasomnias revisited. J Clin Neurophysiol. 1990;7:119-143. http://www.ncbi.nlm.nih.gov/pubmed/2406282?tool=bestpractice.com [2]Broughton R. Behavioral parasomnias. In: Chokroverty S, ed. Sleep disorders medicine: basic science, technical considerations, and clinical aspects. 2nd ed. Boston, MA: Butterworth-Heinemann; 1999:635-660.[3]Brooks S, Kushida CA. Behavioral parasomnias. Curr Psychiatry Rep. 2002;4:363-368. http://www.ncbi.nlm.nih.gov/pubmed/12230965?tool=bestpractice.com [4]Mahowald MW, Bornemann MC, Schenck CH. Parasomnias. Semin Neurol. 2004;24:283-292. http://www.ncbi.nlm.nih.gov/pubmed/15449221?tool=bestpractice.com

They are ubiquitous among children and more frequent than in adults. Most paediatric parasomnias are benign, self-limited, and generally do not persist into adulthood.[5]Mason TB 2nd, Pack AI. Pediatric parasomnias. Sleep. 2007;30:141-151. http://www.ncbi.nlm.nih.gov/pubmed/17326539?tool=bestpractice.com

Parasomnias are considered clinical disorders due to their consequences, which include injury, sleep disruption, adverse health effects, and negative psychosocial effects. They are not a unitary phenomenon but rather may result from a wide variety of conditions, most of which are readily diagnosable, treatable, and explainable.[4]Mahowald MW, Bornemann MC, Schenck CH. Parasomnias. Semin Neurol. 2004;24:283-292. http://www.ncbi.nlm.nih.gov/pubmed/15449221?tool=bestpractice.com [6]Mahowald MW. Overview of parasomnias. In: AASM. National sleep medicine course. Westchester, IL: American Academy of Sleep Medicine; 1999.[7]Kowey PR, Mainchak RA, Rials SJ. Things that go bang in the night. N Engl J Med. 1992;327:1884. http://www.ncbi.nlm.nih.gov/pubmed/1448132?tool=bestpractice.com [8]Thorpy MJ, Glovinsky PB. Parasomnias. Psychiatr Clin North Am. 1987;10:623-639. http://www.ncbi.nlm.nih.gov/pubmed/3332321?tool=bestpractice.com [9]Stores G. Dramatic parasomnias. J R Soc Med. 2001;94:173-176. http://jrsm.rsmjournals.com/cgi/content/full/94/4/173 http://www.ncbi.nlm.nih.gov/pubmed/11317618?tool=bestpractice.com [10]Parkes JD. The parasomnias. Lancet. 1986;2:1021-1025. http://www.ncbi.nlm.nih.gov/pubmed/2877180?tool=bestpractice.com

Parasomnias may include abnormal movements, behaviours, emotions, and autonomic activity, and may be manifestations of central nervous system activation.[2]Broughton R. Behavioral parasomnias. In: Chokroverty S, ed. Sleep disorders medicine: basic science, technical considerations, and clinical aspects. 2nd ed. Boston, MA: Butterworth-Heinemann; 1999:635-660. This topic will cover confusional arousals, sleepwalking, sleep terrors, nightmares, isolated recurrent sleep paralysis, and rapid eye movement sleep behaviour disorder (RBD).

The term 'disorder of arousal' is used to imply incomplete arousal from non-rapid eye movement (NREM) sleep, manifesting with parasomnias. Confusional arousals are characterised by mental confusion or confused behaviour that occurs while the patient is in bed. There is an absence of terror or ambulation outside the bed. When the patient leaves the bed, this is classified as 'sleepwalking'.[11]American Academy of Sleep Medicine. International classification of sleep disorders: diagnostic and coding manual. 3rd ed. Darien, IL: American Academy of Sleep Medicine; 2014.